The thickness of ice varied from half an inch to an inch on cracks and narrow lanes a few yards wide that had just frozen over, to floes drawing one hundred and twenty feet of water, and with hummocks thirty feet above water-level.
During the winter this mass of ice is for the most part quiet, except that at the spring-tides of every month cracks and narrow lanes form, and then freeze rapidly again. Violent wind-storms will cause some disturbance in the ice, the pressure against the hummocks and ragged pinnacles of the large fields causing them to crush any thin ice before them and throw it up in ridges, thus leaving lanes or pools of open water behind, and causing a slow grinding, twisting motion of the pack, which, however, stops, and the open water freezes over, with the cessation of the wind.
In June, July, August, September, October, and November the mass of ice becomes separated into its various parts, and while no water may be visible, the fields and cakes of ice are simply in contact, not frozen together. Then the spring-tides cause much greater motion, and a violent storm will set the whole mass driving before it, with the big floes wheeling and smashing everything in their course until the storm ceases or the movement is stopped by contact with land. Wide lanes and large areas of open water form, and do not freeze over, and the whole ocean is similar to a river in which the ice breaking up in the spring is moving.
This is the time when the ice pours into all the southward-leading channels; that is, between Franz-Josef-Land and Spitzbergen, between Spitzbergen and Iceland, between Iceland and Greenland, and down the American gateway between Greenland and Grant Land.
In none of these places is ice navigation a more serious proposition than in the last. With the exception of brief and infrequent periods when the combination of a fresh southwesterly wind and ebb-tide pushes a fan of open water or loosely drifting ice-cakes out from the northern entrance to this channel between Cape Sheridan and Cape Brevoort, the ice is constantly moving rapidly southward through this outlet. When strong northerly winds combine with spring-flood tides, it rushes through with a violence that is startling.
Entering the widely flaring funnel between Cape Joseph Henry and Cape Stanton, then the narrower one between Cape Sheridan and Repulse Harbor, the ice is compressed between the iron cliffs of Cape Beechey and Polaris Promontory (less than eleven miles), while the swift current of this deep gorge does not permit it to stop, and despite a slight overflow into Newman Bay, is forced sometimes a hundred feet up the cliffs by the resistless momentum and pressure from behind. In mid-channel the pressure forces the ice to rafter, or ride, one field over the other, or the edges of the floes crumble as they come together, and pile up the huge ice-blocks in long ridges fifty or seventy-five feet high. Many of the ice-cakes are forced far under water. One who has seen a big drive of logs which filled the banks of a rapid river pile up and plunge under and ride over when some narrow rock gorge is reached can get a crude idea.
Once through this gorge, Lady Franklin Bay and Peterman Fiord give the ice a chance to expand, and a ship may find here in Hall Basin some open water. Then the walls narrow again between Cape Defosse and Cape Bryant, and farther south the passage is obstructed by Franklin Island and Cape Constitution, till the main channel is less than ten miles wide, before opening out into the wide expanse of Kane Basin, only to be constricted again between Cape Sabine and Cairn Point to a width of twenty-two miles.
When working north in these channels, the only sure way much of the time is to hug the shore, taking advantage of every sheltering point and shallow bit of water, crowding on all steam and forcing ahead a few miles on the ebb-tide, then making fast with all the lines and holding on desperately during the flood-tide, with the ice spinning past only a few feet from the ship’s side. Occasionally courage and judgment give a fifty or hundred mile run in mid-channel, but at its end a firm shore-hold is necessary to prevent being set back by the ever southward rush of the ice, and losing all the hard-earned miles.
A kind of ice navigation that may be encountered by polar ships returning from a voyage late in the season is the tough, leathery, newly forming young ice. A fortunate experience and apprenticeship in the whaler Eagle, in a very late and unusual voyage in 1886, gave me some knowledge of this, which proved invaluable in later years, and on the expedition of 1905–06 kept me from being held in the arctic a year longer with the crippled Roosevelt. For nearly twenty-four hours on the Eagle voyage, her crew, rushing back and forth across her deck timed by Captain Jackman or me, rolled her from side to side, while her engines, going at full speed, slowly drove her out of the clutch of the young ice in Cumberland Sound. A day later, and we probably would not have escaped.
In 1906, when at last, late in September, the battered Roosevelt forced her way out of the heavy ice some miles north of Cairn Point, young ice several inches thick extended all the way to Littleton Island. This ice was just a little too thick for the Roosevelt to steam through, but by rolling her, as we had rolled the Eagle years before, she moved slowly through it. A little later an easterly breeze sprang up, and, with all sails set, these heeled the Roosevelt to just the right angle to have her lee bow turn the ice under her in a steady stream, and she walked along to open water without a hitch.